Mv. Vener, HOW RELIABLE IS THE LIPPINCOTT-SCHROEDER POTENTIAL FOR THE OH-CENTER-DOT-CENTER-DOT-N HYDROGEN-BONDED FRAGMENT IN THE GAS-PHASE, Chemical physics letters, 244(1-2), 1995, pp. 89-92
Ab initio calculations at the MP2 level of theory, with a 6-31 G basis
set which includes polarization functions on the atoms involved in th
e H bond, are performed on the hydrogen-bonded phenol-NH3 complex. The
equilibrium O...N distance (R(e)) is equal to 2.837 Angstrom. The pot
ential profile along the proton coordinate at a fixed O...N distance V
(r, R(e)) has only one minimum. Its shape is verified by calculation o
f the OH stretch frequency. The Lippincott-Schroeder potential is able
to reproduce the shape of the V(r, R(e)) function for systems with an
O-H...N fragment in the gas phase only if some its parameters are cal
ibrated to fit high-level ab initio data.